The Most Dangerous Man On The Planet (ONE SHOT CROSSOVER)
by KryptonianHero
Summary: When kidnapped by anti-alien executioners and tortured, Kara gives in to the fact that she is going to die, only to be saved by a mysterious figure from a dark city. See as Alex, Winn, J'onn and Kara meet the darkest vigilante to have ever existed and see how his dark world contrasts with Kara's. Even Kara needs help sometimes, even if it is Gotham's darkest and famous vigilante.


Kara screamed in agony as the sharp chunk of Kryptonite was shoved into her waist, tearing open the skin, causing a waterfall of blood to pour out. She whimpered when it was then yanked from the wound.

"How does it feel? Alien," her attacker spat at her, grinning evilly at her misfortune.

"You're disgusting," Kara spat back, only then noticing the small trail of blood that was leaving her mouth.

"NO," he yelled, his co workers behind him chuckling, all holding machine guns, "you are the one that is disgusting, you piece of filth," he then literally spat on her, saliva covering her face, "and I will kill you, you little shit."

"Do it then," Kara replied weakly, but she stayed still, smirking on the inside as she felt her powers start to return.

"I wouldn't get cocky alien," he stated, walking over to the wall where a light switch was situated, "cause I'm pretty sure you won't have any strength left when I do this…"

He then flicked the switch up, and suddenly the lights went from being bright yellow, to bright red.

"Quite neat these, aren't they?" he asked, chuckling, "made by CADMUS of course. Emitting the same radiation as a red sun, very much like your home planet's star."

Kara's skin started to pale, from both the huge, gaping wound in her side and the radiation from the lights that she could feel seeping into her body. It was at this moment that Kara actually started to realize that she could die here.

She never even got to sort things out with Alex after Jeremiah's betrayal.

"Just kill me," Kara muttered as her body gave out, all strength leaving her body as she layed on the floor.

"Oh I will," her attacker sneered, "but first, I want to humiliate you. Defile you in front of all of your admires. All those children, the girls who look up to you, seeing you as a weak, pathetic person. And I think you know what I mean when I say 'defile'," he chuckled at the last part, emphasising the last word and Kara felt vomit start to rise up her throat, realizing what they were going to do. It was then that Kara noticed a man setting up a camera in the background. Her attacker pulled out a knife, and slowly walked over to Kara, he knelt down next to her, and she struggled to turn her neck to face him, "you will know humiliation."

Kara then felt him start to cut open her skin, not caring if the knife caught her leg, opening the skin and she felt the blood leak over her skin, she mumbled a weak "no," tears rushing down her face.

He was about to fully cut open the red skirt when the unmistakable sound of gunfire sounded from the hallway, followed by a crack and someone screaming, before a pained chant of 'please, no,' sounded repeatedly outside. The attacker who had been cutting open her skirt looked at the others.

"What the hell was that?"

Before anyone could answer, the door was smashed open, the unconscious body of the guard from outside was thrown inside, his arm had been completely twisted around, the bone sticking out from the skin.

"What the hell?"

Another object was thrown inside the room, Kara recognised it instantly as a flash grenade. The attacker with the knife yelled something, Kara wanted to smile, knowing that someone was going to rescue her, until her eyes widened as she felt the chunk of Kryptonite get shoved directly into her back. He left it in there and her vision started to blur as she felt the life slowly begin to leave her body. She was unable to see what was happening properly, but she could make out someone tearing through the gunmen, sounds of bullets firing, followed by screams of pain, bones cracking and bodies dropping filling the room. She couldn't see who it was but she was grateful for her rescue. Eventually, the commotion stopped and the room was filled with an eerie silence. The last thing Kara saw was the figure walk over to her and crouch down next to her to pick her up before everything went dark.

 _At the DEO_

Alex and J'onn stood around the console in the main hub of the DEO building, both furiously looking for Kara's whereabouts. J'onn looked up to notice Alex smashing her finger into the screen repeatedly.

"Alex. Alex. ALEX," J'onn said repeatedly, getting her attention on the last yell, when she snapped her head up.

"WHAT?" she yelled, before sighing and lowering her head, "I'm sorry."

"Don't be Alex," J'onn replied softly, "I know you're worried but we will find her."

"I know, it's just… what if she's dead?"

"She won't be, I promise."

"It's just, if she is, she died thinking I hate her," Alex replied, trying not to let the tears pour out.

"She could never hate you Alex, you've beaten her up so many times in training and she still loves you," he replied, trying to lighten up the situation with some humour.

"You don't understand, I told her she was no longer family. Who does that?"

"Alex, I-"

But J'onn was cut off when an agent shouted out "WE HAVE AN INTRUDER!"

Everyone quickly turned to face the intruder, guns raised, but J'onn smirked, shaking his head before yelling "GUNS DOWN EVERYONE. WE COULDN'T TOUCH HIM EVEN IF WE TRIED."

Everyone slowly lowered their weapons, still wary of the intruder. And so they should be, as standing at the window entrance of the DEO, used many times by Kara, was a tall, built man, covered in grey and black body armour, emblazoned with a black bat symbol on the chest, his back cover by a sleek, pitch black cape which pooled around his feet, his feet which were covered in metallic boots, his wrists were covered by large gauntlets, each with three sharp fins on the side, the gauntlets themselves featured a huge touch screen on the top, his gloves were thick and metallic, knuckle busters on the each hand, his armoured suit was held together by a large belt which wrapped around his waist, covered in compartments which were filled with a variety of gadgets, his cape was held up by his cowl, which, like the rest of his armour, was metallic and black, with two sharp ears sticking straight up, the only uncovered parts were his eyes which still somehow appeared dark and his mouth, which was flat and emotionless, the cowl connected to the neck and shoulders which were covered in multiple body armour plates which went all down to his shoulders, with the body armour on his arms and torso connecting to the cape and head peace. Standing infront of the entire DEO was the Batman.

In the middle of the uncomfortable silence, Winn broke it by speaking "oh Christ, Batman's real."

It was then that everyone noticed what he was holding. The pale, unconscious body of Supergirl, Batman having had her cape tied around her body, trying to stop the bleeding as much as he could as blood dropped onto the pristine clean floor. After surveying the room, making sure no one was going to attack him, he started to walk down the stairs, his cape dragging along the floor as his boots made loud thumps with every step he took. Kara's arms swung as he walked towards the centre of the room.

J'onn walked over to the comms and pressed down the button, speaking into the microphone and requesting immediate medical attention.

Batman approached them, his tall, built figure intimidating everyone, including J'onn, "she's been severely effected by Red Sun radiation alongside Kryptonite exposure. She's also been severely beaten with multiple Kryptonite stab wounds," he stated as multiple nurses and doctors appeared with a stretcher, he laid her down on the bed, somehow, his suit didn't have a drop of the Kryptonian's blood on it, "you need to get her to your sun lamps immediately and operate on her."

As the medical staff left, Batman overheard one of them ask, "how the hell does he even know we have them?"

"Do you mind explaining to me what happened Batman?" J'onn asked, he then noticed Alex who hadn't moved, "Alex, go, be with her."

Alex quickly nodded before sprinting towards the medical centre.

All attention turned back to Batman who seemed unfazed by all of the attention, "for the past month, I've been tracking an anti-alien activist group which originated in Gotham. I was informed by the GCPD who had received information from an informant that they had kidnapped an alien and planned to broadcast the execution on live TV across the country. I was staking out the building when I was informed of a broadcast inside the building, I was able to hack into their camera setup and saw that the alien they had kidnapped was Kara," everyone's eyes widened when he said her name as if they were old friends, "I instantly knew the severity of the situation and immediately entered the building and removed the threat before treating her wounds, but I didn't have enough equipment to do so, so I brought her here."

"I'm not going to question how you know of our location, which is classified."

"Not even that, was this in Gotham, cause that's like a six hour drive, how did you get here?" Winn asked, cutting off the director.

"I drove," Batman replied simply, before adding "and this wasn't in Gotham. This was in Hollow City, which leads me to asking what she was doing out there by herself."

"We didn't realise that she was investigating this until you just told us, her tracker went offline and we've been looking for her for hours," J'onn replied.

Batman nodded before walking over to the multiple computers setups and pulling a USB out of his belt and plugging it into the computer, he started to quickly type and a few agents looked at J'onn as if asking what they should do, J'onn shook his head, "let him, as it's him, it's safe to say he has a good reason."

As Batman did this, the window opened and suddenly a blur of blue and red shot into the room, there stood Superman, a worried expression on his face, he started to walk over to J'onn, "Alex texted me, said it's bad. What happened?"

J'onn explained to Superman what Batman had said and that's when Superman noticed Batman, who was still downloading data from the computers, he walked over to him.

"You found her?"

"I saved her," Batman bluntly replied, not looking away from the screen.

"Thank you," Superman replied, placing a hand on Batman's armour covered shoulder.

"You don't need to thank me Clark," he replied, and although it was small, J'onn noticed the small grin on Batman's face as Superman's eyes widened.

"What. I don't know who-"

"Cut the crap Clark, wearing glasses and slouching isn't a good disguise," Batman stated as he finished downloading the data. Superman bristled at this and used his X-Ray vision, only to frown when he was unable to see under his mask, to which Batman pointed out, "lead."

Batman turned around, "Clark, J'onn," before walking away.

"Wait, you're not going to wait? See if she's OK," Superman called out, causing Batman to sigh, "please?"

"Fine," Batman caved in, placing his hand to where his ear would be, under the cowl, before speaking into his comms device, "Alfred, I'm going to be a bit preoccupied, tell Dick to take over tonight."

The group stood there for hours, the only ones speaking were Winn and Superman, where Winn was asking multiple questions about Superman's activities, which he answered, trying to pass the time. Everyone else ignored Batman like the plague, one of the new agents accidentally walked into him, dropping all of her files and squeaking out a 'sorry' to which Batman surprised everyone by crouching down and helping pick up the files.

"Err… sir, we've just been informed there's a black tank outside," an agent informed J'onn who immediately got ready to fight this threat until Batman cut in.

"That's my car."

Another few hours passed until Alex walked back in, smiling slightly.

"She's gonna be fine. It took a while and- and there was a lot of problems but they got all of the Kryptonite out. She's under the sunlamps and has already started to heal but- but it's going to scar, really scar, that's how bad it was. And psychologically, we don't know, but they don't think it's going to be good, she was awake at first but she's gone to sleep to heal" Alex then turned to Batman, "thank you. They said she wouldn't have made it if you didn't bring her here, really, thank you."

Batman didn't say anything but he nodded.

"Do they know when she's going to wake up?" Superman asked.

"An hour at the least, that's what they said," she replied, she then frowned and turned to Batman, "you said she was stabbed with Kryptonite, where is it?"

"It's been dealt with."

Everyone eyed him suspiciously but they didn't say anything. It didn't take long for the doctor to come out to the centre, "she's awake. Weak but awake, you can all visit if you want just be careful. Don't overwhelm her," he announced, shifting uncomfortably under Batman's stare. Everyone eventually started to head to the medical centre, with Superman overhearing Alex informing J'onn that she and Kara had patched things up when she was awake after her surgery, with Superman frowning at this. The group eventually reached the medical bay and they all entered the room in which Kara was located, she was under the sunlamps, she was still pale but she was alive, she looked at everyone and smiled.

"Hey," she said, her voice hoarse.

"Hey," everyone replied, smiling at her. It was then that she noticed the tall figure behind them all, her eyes widened.

"Umm… guys," Kara pointed out, gesturing her head to Batman.

"Oh, Kara, this is Batman," Superman pointed out, "he's the man who saved you."

"Oh, thank you," Kara replied, trying to sit up but failing, "I've never heard of you before, what are your abilities then?"

"I don't have any," Batman replied, bluntly.

"You don't?"

"Nope, Batman is literally just a man, and he still managed to beat your cousin in a fight," Winn stated excitedly, earning him a glare from the Man of Steel.

"Wow, it's nice to meet you," Kara said before she started coughing, Alex quickly rushed over with a cup of water.

"It's nice to meet you too Miss Danvers, I've followed your cases, you do tight and efficient work. But I need to get back to Gotham, and this is clearly a time for family," Batman replied. Kara's eyes wide when he said her name.

Superman turned around to tell him to stay only for everyone to notice that he'd somehow vanished, "how?"

"He is so awesome," Winn exclaimed, "he's even better than the legends say."

"Legends?" Kara asked.

"Yeah, not many people knew he existed," Winn replied, "I did, but when I first saw him earlier, it was still hard to believe he actually existed."

"But how did he know my name, did you tell him?" she accused Superman, who held up his hands defensively.

"Hey, I didn't say anything, I didn't even tell him my name yet he knew."

"Batman is one of the most dangerous people on the planet, and he's smart, he was bound to know our identities," J'onn pointed out.

"He's one of the most dangerous people on Earth? But he's just a man," Kara pointed out, not believing this.

"Yes he is, but he still defeated your cousin in a fight, even with Clark under the influence of red Kryptonite and he has single handedly defeated every single assassin that has ever been paid to kill him."

"Jesus," Alex muttered under her breath.

Out of nowhere, a doctor appeared, "I'm sorry but Miss Danvers needs to rest now, so I need you all to leave please."

Everyone nodded, Alex leant down to kiss Kara's forehead, "I love you sis, you know that right?"

Kara nodded, tears forming in her eyes, "I do, I love you too Alex. I love all of you guys."

Everyone started to leave when Kara called out.

"Hey J'onn, do you think me and Batman could team up one day?"

"Oh no," J'onn replied, chuckling, "he's not really a people person, from what I've heard."

Kara nodded before lying back down, her thoughts drifting to her saviour from earlier.

 _Later that night_

On the streets of Gotham, a terrified couple were pinned up against the wall in an alleyway, the muggers demanding their money and belongings. The couples eyes widened when something appeared from behind the criminals, whose eyes widened in fear when they realised what it was.

"Oh crap," one of them muttered before they were instantly yanked back by the Batman, the rest of the muggers running away screaming in terror as the Dark Knight took out the mugger, the couple scurrying away in the process. Batman looked up and noticed the sky was suddenly illuminated by a symbol of a Bat. He pulled out his grappling gun, firing it and disappearing from sight into the night.

 _ **SO WHAT DID YOU GUYS THINK. PLEASE LEAVE A COMMENT AND GIVE ME SUGGESTIONS ON MORE ONE SHOTS AND TELL ME WHAT YOU THOUGHT OF THIS ONE. DID YOU LIKE MY VERSION OF THE DARK KNIGHT (IF YOU DIDN'T GUESS IT, WHEN I DESCRIBED WHAT THE BATMAN LOOKED LIKE, I BASED THIS ONE'S SUIT OFF THE ARKHAM KNIGHT BATSUIT), I'VE BEEN DEBATING WHETHER TO WRITE A BATMAN/SUPERGIRL ONE SHOT FOR A WHILE, TRYING TO FIGURE OUT HOW TO BRING THIS DARK, SCARY CHARATCER OF BATMAN INTO SUPERGIRLS WORLD, WHICH IS OBVIOUSLY BRIGHT AND FILLED WITH HOPE.**_

 _ **I AM VENGEANCE. I AM THE NIGHT. I AM BATMAN.**_


End file.
